JPH08146234A - Manufacture of composite monofilament for light/picture transmission and composite monofilament fabricated by manufacture thereof - Google Patents

Abstract

PURPOSE: To use a polymer material for the manufacture of a composite monofilament having a continuous refraction factor distribution from the surface layer to the center for transmitting light and images. CONSTITUTION: A composite monofilament 24 is extruded from two polymer solutions containing two different kinds of monomars having different refraction factors and, then, the two kinds of monomars are diffused in a diffusion zone in a direction opposite to each other before the composite monofilament 24 cures, thereby providing a continuous manufacturing method. The outer layer of the composite monofilament 24 is removed before or after a curing process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite monofilament for light / image transmission (hereinafter also referred to as a polymer material column for light / image transmission) by an extrusion process, and more specifically, a different refraction index A polymeric material solution containing two monomers having an index is extruded through a mold so that the monomers diffuse into each other in the diffusion region to form a polymeric material column having a continuous refractive index distribution. The present invention relates to a method for producing a polymer material column for light / image transmission and a polymer column for light / image transmission produced by the production method.

[0002]

2. Description of the Related Art An optical transmission column having a continuous refractive index distribution from the surface layer toward the center of the column (herein, the column means a monofilament or a composite monofilament, the same applies hereinafter) is made of glass elsewhere. Has been. However, the optical transmission column of this method has a very low production rate and a very high cost in manufacturing. The glass optical transmission column also has a problem that it is poor in flexibility for various applications. This type of glass optical transmission column is disclosed in Japanese Patent Laid-Open No. 47-816.
No. 6,086,045.

Others have proposed a method for producing an optical transmission column having a continuous refractive index distribution from the surface layer toward the center of the column, using a polymer material. One such method is an ion that continuously changes the concentration of metal ions from the column center to the surface layer so that a polymer material optical transmission column having a continuous refractive index distribution from the surface layer to the column center can be obtained. A synthetic resin filament is produced by graft polymerization. Such a method is described in Japanese Patent Laid-Open No. 47-26913.
Alternatively, it has been proposed to make filaments from a mixture of two or more transparent polymeric resins having different refractive indices. After a special solvent treatment, a part of the resin mixture is dissolved to obtain an optical transmission column. This technique is disclosed in Japanese Patent Laid-Open No. 47-28059. In addition, in the method disclosed in Japanese Unexamined Patent Publication No. 54-30301, two monomers having different refractive indexes are used, and a continuous refractive index distribution is obtained from the surface layer toward the center of the column. It teaches polymerization methods to form polymeric materials. Still another method discloses a method of diffusing the monomer in the surface layer of the block copolymer so that the content of the monomer in the block copolymer is continuously distributed from the surface layer to the center of the block copolymer. It was Then, a polymerization reaction is carried out to produce an optical transmission column having a continuous refractive index distribution. These techniques are disclosed in Japanese Patent Laid-Open No.
No. 5857, 56-37521 and 57-29682. It should be noted that all of the above disclosed methods and techniques are carried out in non-continuous batch operations.

In order to overcome the deficiency of the non-continuous production process, the continuous production method is disclosed in Japanese Patent Laid-Open Nos. 1-1896021 and 1-25.
3704, 2-16505 and 2-233104. In this technique, a polymeric material and a monomer are mixed in a mixing tank and heated until the polymeric material dissolves in the monomer and is uniformly mixed. Then, the monofilament is extruded from the mold and sent to the gas evaporator. Gas is fed into the evaporator so that the monomers evaporate from the monofilament surface. In this way, a monofilament in which the concentration of the monomer is continuously distributed is formed. After the curing treatment, a polymer material monofilament having a continuous refractive index distribution from its surface layer toward the center is obtained.

The above method has several drawbacks:
For example, the time required for diffusion is long (therefore, it takes a long time to manufacture and the production speed is low), it is difficult to select the optimum production conditions, and the reproducibility is lacking. These problems must be resolved before the method is applied to the production floor.

[0006]

Therefore, an object of the present invention is to provide an optical transmission column having a continuous refractive index distribution from its surface layer (or surface, represented by the surface layer below) toward the center of the column. It is to provide a method of manufacturing from.

Another object of the present invention is to provide a method for producing an optical transmission column having a continuous refractive index distribution in the column from a polymer material, that is, a step which can be actually produced.

A further object of the present invention is to provide a method capable of producing an optical transmission column having a continuous refractive index distribution from its surface layer toward the center of the column from a polymer material at a high production rate. is there.

Still another object of the present invention is to manufacture an optical transmission column having a continuous refractive index distribution from its surface layer toward the center of the column from a polymeric material with a high level of reproducibility in a continuous process. It is to provide a method of obtaining.

[0010]

According to the present invention, there is provided a method for producing an optical transmission column having a continuous refractive index distribution from a surface layer toward a column center from a polymer material in a continuous production process.

In a preferred embodiment, extruding a composite monofilament from a solution of a polymeric material containing two monomers having different refractive indices, and allowing the monomers to diffuse into each other before the composite monofilament is cured. A continuous manufacturing method is provided by diffusing in a diffusing region to match. Then, after the curing step, a portion of the composite monofilament is layered from the surface.

In an alternative embodiment, by extruding the composite monofilament from a solution of a polymeric material containing two monomers having different refractive indices and allowing the monomers to diffuse into each other in the composite monofilament. , A continuous manufacturing process of optical / image transmission columns is carried out. A portion of the composite monofilament is then layered from the surface before it is cured.

[0013]

According to the preferred or alternative embodiments described above,
It is possible to produce a light / image transmitting polymer material column having a refractive index distribution in the column and capable of transmitting an image. This kind of polymer material column for light / image transmission includes an optical lens,
It can be used as an optical fiber or an optical integrated circuit.

According to the present invention, the above-mentioned light / image transmission column having high optical transparency can be produced in a continuous process.

[0015]

The present invention discloses a method for producing a light / image transmission column having a continuous refractive index distribution from the surface layer toward the center of the column from a polymer material in a continuous production process.

In the present invention, a first mixture of one polymer material and one monomer which is a solvent for the polymer material or one polymer material and a monomer which is a solvent for the polymer material A first mixture with two or more monomers comprising a body,
A second mixture of one polymeric material and one monomer different from the monomer contained in the first mixture is extruded through a concentric mold into a bilayer composite monofilament. . The separate monomers are diffused in the diffusion region of the composite monofilament until the two monomers diffuse into each other. The composite monofilament is then cured and a portion of the composite monofilament is layered from the surface.

In a second embodiment, before the composite monofilament is cured, a portion of the composite monofilament is first removed in layers from the surface. Either embodiment produces a polymer material column for optical / image transmission having a continuous refractive index distribution from the surface layer toward the center of the column for the purpose of image transmission.

The polymer material used in the present invention is polymethylmethacrylate, or methylmethacrylate and other monomers such as ethylmethacrylate and n-methacrylate.
Propyl, isopropyl methacrylate, methacrylic acid t
-Butyl, cyclohexyl methacrylate, fluoroalkyl methacrylate, methyl 2-hydroxymethacrylate, ethyl 2-phenoxymethacrylate, glyceryl methacrylate, benzyl methacrylate, phenyl methacrylate. The polymeric material may be a copolymer of methyl methacrylate with an acrylate salt such as methyl acrylate, ethyl acrylate, propyl acrylate or fluoroalkyl acrylate. Further, the polymer material may be a copolymer of methyl methacrylate and methacrylic acid such as acrylic acid.

The first monomer B and the second monomer C used in the present invention include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and methacrylic acid. Isopropyl acid, t-butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, fluoroalkyl methacrylate, methyl 2-hydroxymethacrylate, ethyl 2-phenoxymethacrylate, glaryl methacrylate, and methyl acrylate, acrylic. Acrylic acid type monomers such as ethyl acrylate, propyl acrylate or fluoroalkyl acrylate may be included.

To carry out the present invention, a first mixture of polymeric material of methyl methacrylate and monomer B and a second mixture of polymeric material of methyl methacrylate and monomer C are produced. To be done. Heat activated curing agent or UV during production
Activated hardener is added to the mixture. The content of the monomer B or the monomer C in the mixture is about 10% of the total mixture.
To about 80 weight percent, preferably between about 30 and about 80 weight percent, and more preferably about 4
The range is between 0 and about 70 weight percent. The heat-activated curing agents commonly used in the present invention are peroxide type curing agents, while typical UV-activated curing agents are benzophenone and 1-hydroxycyclohexyl phenyl ketone.

In the present invention, polymeric material / monomer B
And when two mixtures of polymeric material / monomer C are made, the viscosity of the resulting mixture ranges between about 10 ² and 10 ⁵ poise. When the viscosity is lower than 10 ² poise,
The composite monofilaments are frequently cut, making it difficult to extrude the aforementioned composite monofilaments. Viscosity 10
^When it is higher than ⁵ poise, the extrusion process of the composite monofilament is practically difficult.

In the next processing step, two different mixtures are extruded through concentric molds to form a composite monofilament with inner and outer layers of different materials. The extrusion process is performed according to the following standard industry practice. After the extrusion treatment, the monomer B and the monomer C diffuse into each other through the diffusion region which is the boundary between the inner and outer layers. The extruded composite monofilament is then cured by either heat activated or UV activated means, followed by a portion of the composite monofilament being layered from the surface to complete the process.

In order to obtain excellent image transmission properties, the distribution of refractive index should follow a quadratic parabolic curve. After the completion of the diffusion treatment of the monomer B and the monomer C, the layered portion having a certain thickness from the surface of the composite monofilament (hereinafter referred to as the outermost layer) no longer has a refractive index distribution according to such a quadratic parabolic curve. It became clear that it would not be shown. Therefore, in order to maintain the image transmission of the composite monofilament, it is necessary to remove the outermost layer of the composite monofilament. A suitable thickness of the outermost layer to be removed is between about 10% and about 60% of the diameter of the composite monofilament,
Preferably it is between about 20% and about 50%, and more preferably between about 25% and about 40%.

In an alternative embodiment, a portion of the composite monofilament is first layered (said outermost layer) from the surface before it is cured. Therefore, a high-quality optical / image transmission column having a continuous refractive index distribution and capable of transmitting an image can be obtained.

In the composite monofilament made according to the present invention, the volume ratio of the inner and outer layers of the composite monofilament extruded through the concentric mold is between about 1: 1 and about 1: 100, preferably the above-mentioned inner and outer layers. The volume ratio is between about 1: 1 and about 1:10, and the more preferred volume ratio of the inner and outer layers is between about 1: 1 and about 1: 5.

As an additional processing step, during the diffusion of the two monomers of the composite monofilament, the diffusion zone may be heated in a conventional manner, if desired, to further facilitate diffusion. However, such heating should not cause any further polymerization in the composite monofilament.

By subjecting the above-mentioned composite monofilament to UV irradiation or heat treatment, the curing treatment of the composite monofilament may be accelerated, but it is not always necessary. Suitable irradiation sources are, for example, carbon arc lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, electrodeless lamps, xenon lamps or laser sources used at wavelengths between 150 nm and 600 nm.

Now, description will be given with reference to the diagram (FIG. 1) showing the outline of the apparatus used in the present invention. The material supply tank 10 contains a solution of one polymer material and at least one monomer B, and the material supply tank 12 contains one solution.
A solution of one polymeric material and at least one monomer C is charged. The heating devices 14 and 16 are used to promote the dissolution of the polymeric material in the monomers B and C. The solution is normally heated to a predetermined temperature above room temperature. Constant volume pumps 18 and 20 are used to pump the two mixtures into the concentric mold 22 at a predetermined flow rate. The double layer composite monofilament 24 is formed by the molding die 22.
Extruded from the orifice (not shown) in the closed diffusion zone 2
Sent to 6. While advancing in the diffusion zone 26 for a time not shorter than 1 second, the monomer in the outer layer and the monomer in the inner layer diffuse with each other to exert the effect of continuous refractive index distribution on the composite monofilament. Occurs. At the exit end of the diffusion zone 26, a separating device 28 is provided with the composite monofilament 2
Separate the outermost layer of 4. This separating device may be mechanical, optical or any other means. The composite monofilament 24 is then sent to the cure zone 30 where it is cured. The composite monofilament 24 is then removed by the unload roll 34 through the roller 32.

Other objects, features and benefits of the present invention will be apparent upon consideration of the accompanying drawings which show a specification and overview of the apparatus used in the method of the present invention.

Example 1 The first mixture used in the inner layer (ie, the core) was 50 parts by weight of methyl methacrylate, 50 parts by weight of benzyl methacrylate monomer, and 0.2 parts by weight of 1-hydroxycyclohexyl phenyl ketone. , And 0.1 parts by weight of hydroquinone. The total parts by weight of the first mixture is approximately 100. The second mixture used in the outer layer (i.e., the clad) was 50 parts by weight of methyl methacrylate, 50 parts by weight of the monomer of methyl methacrylate, 0.2 parts by weight of 1-hydrooxycyclohexyl phenyl ketone and 0.2 parts of hydroquinone.
It consists of 1 part by weight. The total weight of the second mixture is approximately 1
00. The two mixtures are pumped simultaneously through a concentric mold orifice.

Using the apparatus shown in FIG. 1, the composite monofilament 24 is passed through a closed diffusion zone of about 20 cm long, after which the composite monofilament 24 is cured into four equally spaced 60 cm long cures. Pass through a curing zone 30 containing a high pressure mercury lamp. The volume ratio of inner layer to outer layer of the resulting composite monofilament is 1: 3. Thereafter, the outermost layer of the composite monofilament 24 is removed by the separating device 28.

After removing the outermost layer, the composite monofilament is
It has a diameter of 1 mm. The refractive index distribution was found to be 1.525 at the center of the composite monofilament and 1.503 at the outer layer of the composite monofilament. The refractive index data were measured using an Interphako interference microscope. In addition, the composite monofilament is
It is also apparent that it showed a continuous decrease in refractive index from the center of the composite monofilament to the outer periphery of the composite monofilament. There is no distortion in the image transmitted by the composite monofilament for light / image transmission.

Example 2 The first mixture used in the inner layer of the composite monofilament was 50 parts by weight of polymethylmethacrylate, 50 parts by weight of benzyl methacrylate monomer, and 0.2 parts by weight of 1-hydroxycyclohexylphenylketone. , And 0.1 parts by weight of hydroquinone. The total parts by weight of the first mixture is approximately 100. The second mixture used in the outer layer is 50 parts by weight of polymethylmethacrylate polymer material,
50 parts by weight of 2,2,3,3-tetrafluoropropylmethacrylic acid monomer, 0.2 parts by weight of 1-hydroxycyclohexyl phenyl ketone, and hydroquinone 0.1.
It is a mixture of parts by weight. The total weight of the second mixture is approximately 100. The two mixtures are extruded simultaneously through concentric mold orifices to form composite monofilaments.

The composite monofilament is then passed through the 40 cm long enclosed diffusion zone shown in FIG. The volume ratio of inner layer to outer layer of the resulting composite monofilament is 1: 3. The outermost layer of the composite monofilament is removed before the composite monofilament is cured. The composite monofilament is then passed through a cure zone equipped with four 60 cm long 60 watt output high pressure mercury lamps for curing that are equally spaced.

The obtained composite monofilament has a diameter of 1 mm.
Has a diameter of. The refractive index measured at the composite monofilament center is 1.522, while that measured at the outermost composite monofilament layer is 1.480. It has been observed that the refractive index continuously decreases from the center of the composite monofilament to the outermost layer of the composite monofilament. The image transmitted by the composite monofilament is not distorted.

A second composite monofilament was also obtained having a different inner layer to outer layer volume ratio (before removal of the outermost layer) of 1: 2. The diameter of the obtained composite monofilament is kept at 1 mm. The index of refraction measured at the center of the composite monofilament is 1.522, while that measured at the outermost layer of the composite monofilament is 1.483. The composite monofilament shows a continuous decrease in refractive index value from the center of the composite monofilament to the outermost layer of the composite monofilament. No distortion was observed in the image transmitted by the composite monofilament.

A third composite monofilament having a volume ratio of inner to outer layer (before removal of the outermost layer) of 1: 1 was also obtained. The diameter of the obtained composite monofilament is again kept at 1 mm. The index of refraction was measured using an Interphako interference microscope and was determined to be 1.518 at the composite monofilament center and 1.491 at the composite monofilament outermost layer. The composite monofilament again exhibits a continuous decrease in refractive index from the center of the composite monofilament to the outermost layer. The image transmitted by the composite monofilament is not distorted.

While the foregoing has been set forth to describe the invention, it is to be understood that the terminology used is not intended to be limiting, but rather intended to be descriptive.

Moreover, while the present invention has been described in terms of preferred and alternative embodiments thereof, it is contemplated that one of ordinary skill in the art would readily apply these teachings to other possible variations of the invention. .

Embodiments of the invention in which an exclusive property or patent right is claimed are limited as set forth in the following claims.

[0041]

In a preferred embodiment, a composite monofilament is extruded from a polymeric material solution containing two monomers having different refractive indices, and the monomers are mixed together before the composite monofilament is cured. A continuous manufacturing method is provided by diffusing in a diffusion region so as to diffuse into each other. Then, after the curing step, a portion of the composite monofilament is layered from the surface.

In an alternative embodiment, by extruding the composite monofilament from a solution of a polymeric material containing two monomers having different refractive indices and allowing the monomers to diffuse into each other in the composite monofilament. , A continuous manufacturing process of optical / image transmission columns is carried out. A portion of the composite monofilament is then layered from the surface before it is cured.

According to the preferred or alternative embodiment described above, a light / optical device having a refractive index profile in the column and capable of transmitting an image
A polymeric material column for image transmission can be produced.
This kind of polymer material column for light / image transmission can be used as an optical lens, an optical fiber, or an optical integrated circuit.

According to the present invention, the above-mentioned light / image transmission column having a high optical transparency can be produced in a continuous process.

Further, according to the present invention, there is provided a method for producing an optical transmission column having a continuous refractive index distribution from the surface layer toward the center of the column from a polymer material in a continuous production process.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an apparatus for producing a composite monofilament for optical / image transmission.

[Explanation of symbols]

 10 Material Supply Tank 12 Material Supply Tank 14 Heating Device 16 Heating Device 18 Metering Pump 20 Metering Pump 22 Concentric Mold 24 Composite Monofilament 26 Closed Diffusion Zone 28 Separator 30 Curing Zone 32 Roller 34 Roll

Claims (20)

[Claims] 1. Preparing a first mixture of a first polymeric material and at least one first monomer that is a solvent for the first polymeric material; a second polymeric material. And at least 1 which is a solvent for the second polymeric material
A mixture of two second monomers, the at least one second monomer being different from the at least one first monomer. Preparing a mixture; combining the first and the second mixture so as to obtain a composite monofilament having an inner layer and an outer layer formed by the first and the second mixture with an interface therebetween. Flowing through a concentric mold with an orifice; for a time sufficient to diffuse a sufficient amount of the first and second monomers across the interface to the outer and inner layers, respectively. Passing the composite monofilament through a diffuser; passing the composite monofilament into a curing jig so that the composite monofilament is cured by irradiation energy; It consists of removing a portion of the composite monofilament from the surface in layers by passing the filament through a separator and has a continuous refractive index distribution from the center of the composite monofilament useful for light / image transmission to the outermost layer of the composite monofilament. A manufacturing method of composite monofilament made of polymer material. 2. The first polymer material and the second polymer material are polymethylmethacrylate and methylmethacrylate and ethylmethacrylate, n-propylmethacrylate, isopropylmethacrylate, t-methacrylate. Butyl, cyclohexyl methacrylate, fluoroalkyl methacrylate, methyl 2-hydroxymethacrylate, 2-
Copolymer of monomers selected from the group consisting of ethyl phenoxymethacrylate, glyceryl methacrylate, benzyl methacrylate, phenyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, fluoroalkyl acrylate and acrylic acid. The method of claim 1, wherein the method is selected from the group consisting of: 3. The at least one first monomer and the at least one second monomer are methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, methacrylic acid. t-butyl, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, fluoroalkyl methacrylate, methyl 2-hydroxymethacrylate, ethyl 2-phenoxymethacrylate, glaryl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate And a fluoroalkyl acrylate is selected from the group consisting of: 4. The method of claim 1, wherein at least one of the first mixture and the second mixture is heated to a predetermined temperature to promote formation of the mixture. 5. The method of claim 1, wherein the composite monofilament formed has a diameter of between about 0.1 mm and about 5 mm. 6. The method of claim 1, wherein at least one of the first mixture and the second mixture further comprises a catalyst. 7. The volume ratio of the inner layer to the outer layer is about 1:
The method of claim 1, wherein the method is between 1 and about 1: 100. 8. The method according to claim 1, wherein the volume ratio of the inner layer to the outer layer is preferably between about 1: 1 and about 1:10. 9. A process according to claim 1, wherein said separating device is selected from the group consisting of mechanical means, optical means and hydraulic means. 10. The method according to claim 1, wherein the separation treatment of removing a part of the composite monofilament from the surface in layers is performed before the curing treatment. 11. The layered portion from which a portion of the composite monofilament is layered off the surface is characterized by a thickness of between about 10% and about 60% of the diameter of the composite monofilament. The method according to item 1. 12. The layered portion from which a portion of the composite monofilament is layered away from the surface is preferably between about 20% and about 50% of the diameter of the composite monofilament. The manufacturing method according to claim 1. 13. The layered portion from which a portion of the composite monofilament is layered away from the surface is more preferably between about 25% and about 40% of the diameter of the composite monofilament. The method according to claim 1, which is characterized in that: 14. An inner layer formed by polymerization of a first polymeric material dissolved in at least one first monomer solvent, and a second layer dissolved in at least one second monomer solvent. A composite monofilament formed from an outer layer formed by the polymerization of the polymeric material of claim 1, wherein a sufficient amount of at least one first monomer to diffuse into the outer layer and a sufficient amount of diffuse to the inner layer. At least one second monomer is composed of the inner layer and the outer layer that form a continuous refractive index distribution from the center of the inner layer of the composite monofilament to the surface of the outer layer (the surface of the composite monofilament). A composite monofilament made from a polymer material. 15. The first and second polymer materials are polymethylmethacrylate, methylmethacrylate and ethylmethacrylate, n-propylmethacrylate, isopropylmethacrylate, t-butylmethacrylate, methacrylic acid. Cyclohexyl, fluoroalkyl methacrylate, 2-hydroxymethyl methacrylate, 2-phenoxyethyl methacrylate, glyceryl methacrylate, benzyl methacrylate, phenyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, fluoroalkyl acrylate and 15. The composite monofilament according to claim 14, wherein the composite monofilament is selected from the group consisting of copolymers with monomers selected from the group consisting of acrylic acid. 16. The at least one first monomer solvent and the at least one second monomer solvent are methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, T-butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, fluoroalkyl methacrylate, 2-hydroxymethyl methacrylate,
15. The composite monofilament of claim 14 selected from the group consisting of 2-phenoxyethyl methacrylate, glaryl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate and fluoroalkyl acrylate. 17. The composite monofilament comprises about 0.
15. The composite monofilament of claim 14, having a diameter of between 1 mm and about 5 mm. 18. The composite monofilament according to claim 14, wherein at least one of the polymerization treatments for the inner layer and the outer layer is supported by a catalyst. 19. The composite monofilament of claim 14, wherein the volume ratio of the inner layer to the outer layer is between about 1: 1 and about 1: 100. 20. The volume ratio of the inner layer to the outer layer is preferably between about 1: 1 and about 1:10.
The described composite monofilament.